Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a semi-automatic or automatic arc welding process in which a continuous and consumable wire electrode (“welding wire”) and a shielding gas are fed through a welding gun.
Pulse spray metal transfer (GMAW-P) uses high energy of Axial Spray Metal Transfer and alternates this high energy (peak) current with a lower energy (background) current. Each cycle is referred to as a period and the period can repeat several hundred times per second. Spray or pulsed spray welding processes are free flight transfers in which a droplet formed detaches from the wire, crosses the plasma, and into the weld pool.
Pulsed energy produces desirable fusion characteristics and reduces the heat input considerably when compared to axial spray transfer or other welding processes. The dynamics of the pulse permit the use of GMAW-P for out-of-position welding. Therefore, it is easily seen that what is needed is a dynamic way to provide a more accurate method for detection of the droplet detaching (and the droplet detachment point) from a wire.